From: Thomas Weißschuh <linux@weissschuh.net>
Date: Mon, 16 Dec 2024 17:25:08 +0000 (+0100)
Subject: params: Prepare for 'const struct module_attribute *'
X-Git-Tag: v6.14-rc1~82^2~11
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=30d446088866db99b0cf9e6af58ac1427f51f3dd;p=thirdparty%2Fkernel%2Flinux.git

params: Prepare for 'const struct module_attribute *'

The 'struct module_attribute' sysfs callbacks are about to change to
receive a 'const struct module_attribute *' parameter.
Prepare for that by avoid casting away the constness through
container_of() and using const pointers to 'struct param_attribute'.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Reviewed-by: Petr Pavlu <petr.pavlu@suse.com>
Link: https://lore.kernel.org/r/20241216-sysfs-const-attr-module-v1-1-3790b53e0abf@weissschuh.net
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
---

diff --git a/kernel/params.c b/kernel/params.c
index 2e447f8ae183e..e90733824528e 100644
--- a/kernel/params.c
+++ b/kernel/params.c
@@ -555,13 +555,13 @@ struct module_param_attrs
 };
 
 #ifdef CONFIG_SYSFS
-#define to_param_attr(n) container_of(n, struct param_attribute, mattr)
+#define to_param_attr(n) container_of_const(n, struct param_attribute, mattr)
 
 static ssize_t param_attr_show(struct module_attribute *mattr,
 			       struct module_kobject *mk, char *buf)
 {
 	int count;
-	struct param_attribute *attribute = to_param_attr(mattr);
+	const struct param_attribute *attribute = to_param_attr(mattr);
 
 	if (!attribute->param->ops->get)
 		return -EPERM;
@@ -578,7 +578,7 @@ static ssize_t param_attr_store(struct module_attribute *mattr,
 				const char *buf, size_t len)
 {
  	int err;
-	struct param_attribute *attribute = to_param_attr(mattr);
+	const struct param_attribute *attribute = to_param_attr(mattr);
 
 	if (!attribute->param->ops->set)
 		return -EPERM;